This deivce and method are particularly adapted so as to be used in spatial applications, such as on artificial satellites and orbital stations, to which secured are sub-systems or items of equipment, such as antennae or solar panels to be freed after the placing in orbit. The temporary linking device used in spatial applications usually include a holding mechanism which, both before and during orbiting, provides the link between the lengthening piece and the body of the satellite. To this effect, this mechanism applies a mechanical holding tension between the two elements. Depending on the case involved, this mechanism is constituted by either a metallic tension rod or "Kevlar" (registered trade mark) tension rod, or by a tiltable yoke or swivel joined, for example, to the lengthening piece seucred to the satellite.
The temperary linking devices also include means for freeing the holding mechanism.
In the majority of cases, these freeing means include pyrotechnic components. In particular, pyrotechnic shears are usually associated with metallic tension rods to control rupture of said means. Similarly, the swivels are kept in place against the action of a spring by means of a locking mechanism, the latter being freed by either cutting one rod of this mechanism with a pyrotechnic shear, or by a cable activated by a pyromechanism and simultaneously freeing the locking mechanisms of several linking devices.
In "Kevlar" tension rods, the freeing means include a heating resistor encompassing the tension rod so as to control its prolongation or melting.
In existing temporary linking devices, all the freeing means currently have serious drawbacks.
First of all, the pyrotechnic components frequently present a restrictive mass and spatial requirement and induce impacts when used. In addition, the pyrotechnic components strictly need to be sealed so as to avoid polluting the equipment embarked on the satellites, especially when this equipment includes optics. Another drawback of the pyrotechnic components is that they possess extremely limited operating ranges as regards the operating performances and environments, which in each case results in having to develop a new product or provide long and costly qualification additions. The high cost of these components thus limits the number of tests required. Finally, the nature of the pyrotechnic components imposes special precautions needing to be taken at the time they are used and, when a lengthening piece is secured at several points, results in accordingly multiplying the number of pyrotechnic orders on the satellite.
Furthermore, the "Kevlar" tension rod mechanisms freed by means of a heating resistor are expensive and require high electric energy, especially when they are required to melt the tension rod. In addition , the melting of the Kevlar rod may result in excessively polluting adjacent components, for example in optical devices including mirrors or lenses.